General Photonics PMDPro PMD-1000 User manual

PMD-1000
PMDPro™ Polarization Optimized PMD Source
Operation Manual
Version 2.1
November 16, 2015
General Photonics Corp. Ph: [phone]
5228 Edison Ave. Fax: [phone]
Chino, CA 91710 USA www.generalphotonics.com
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SAFETY CONSIDERATIONS
The following safety precautions must be observed during operation, service and repair
of this instrument. Failure to comply with these precautions or with specific warnings
elsewhere in this manual violates safety standards of design, manufacture, and intended
use of the instrument. General Photonics Corp. assumes no liability for customers’ failure
to comply with these requirements.
•Before operation, the user should inspect the instrument and
review the manual carefully.
•The instrument’s rear panel includes a chassis ground terminal for electrical
safety.
•Make sure that the instrument is in a secured work environment (in terms of
temperature, humidity, electrical power, hazard due to fire or shock, etc.) for
proper operation.
•Standard laser safety procedures should be followed during operation.
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Table of Contents:
Section 1. Specifications:.................................................................................................. 5
Section 2. Overview: ........................................................................................................ 6
Section 3. Feature Description:....................................................................................... 7
3.1 Optical Features:...................................................................................................... 7
3.2 Electrical Features:.................................................................................................. 8
Section 4. Operation Instructions:................................................................................ 11
4.1 Unpacking .............................................................................................................. 11
4.2 Front Panel Operation........................................................................................... 11
4.2.1 MONITOR:.................................................................................................... 12
4.2.2 SETUP: ........................................................................................................... 13
4.2.3 PMDE: ............................................................................................................ 15
4.2.4 SOP: ................................................................................................................ 29
4.2.5 WSOP: ............................................................................................................ 37
4.2.6 PMDC:............................................................................................................ 39
4.2.7 Manual:........................................................................................................... 42
4.2.8 STORE:........................................................................................................... 43
4.2.9 RECALL:........................................................................................................ 45
4.3 Remote Control Operation..................................................................................... 46
4.3.1 System Requirements ............................................................................. 46
4.3.2 Installation............................................................................................... 46
4.3.3 RS-232 Connection.................................................................................. 49
4.3.4 USB Connection...................................................................................... 49
4.3.5 GPIB Connection.................................................................................... 50
4.3.6 Ethernet Connection............................................................................... 50
4.3.7 Control Program Interface.................................................................... 55
Monitor Screen.................................................................................................... 56
Front Panel Functions:....................................................................................... 58
PMDE................................................................................................................... 58
SOP: ..................................................................................................................... 61
PMDC:................................................................................................................. 63
MONITOR:......................................................................................................... 64
MANUAL:........................................................................................................... 65
Advanced Functions:.......................................................................................... 66
ADVANCED PMDE:.......................................................................................... 66
PMD Measurement and Long-term Monitoring:............................................ 80
PMD Measurement:............................................................................................ 80
Long Term PMD Monitor: ................................................................................ 86
Setup: ................................................................................................................... 88
Store/Recall: ........................................................................................................ 89
PMD Calculation................................................................................................. 92
4.3.8 Remote Control Command List ............................................................ 93
Section 5. Applications:................................................................................................ 101
5.1 PMD Tolerance Testing with Polarization Multiplexed Signals.................... 101
5.2. PMD Mitigation in 40Gb/s systems.................................................................. 105
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5.3 Instruments required for PMD related tests.................................................... 108
5.4 Desirable features for a PMD source................................................................ 111
5.5 The polarization optimized PMD source.......................................................... 111
5.6 Advantages and applications of the polarization optimized PMD source..... 114
Section 6. Troubleshooting:.......................................................................................... 116
Section 7. Technical Support ....................................................................................... 117
Appendix A: ITU Grid Channel Lookup Table......................................................... 118
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Section 1. Specifications:
Physical Features:
Dimensions 2U, 19 inch ¾ rack width
3.5” (H) ×14” (W) ×14” (L)
Connector Type FC/PC, FC/APC, SC/PC, or SC/APC
Operating Temperature 10 °C to 50 °C
Storage Temperature −20 °C to 60°C
Optical Characteristics (Typical):
Operating Wavelength Range C band or L band
Insertion Loss 5.0 dB @1550 nm (90 ps version)
5.5 dB @1550 nm (180 ps version)
Input Power Range −10 to 10 dBm
Return Loss 50 dB
DGD Range 0 to 91 ps or
0.36 to 182.4 ps
DGD Resolution
90 ps range 180 ps range
Discrete mode 0.357 ps 0.714 ps
Quasi-continuous mode 0.1 ps 0.2 ps
2nd-order PMD Range 2000 ps2(90-ps range)
8100 ps2(180-ps range)
PMD Variation Time 1 ms (minimum)
SOP Alignment Accuracy ±2° at 23±5°C.
SOP Tracking Speed 10π/s
DOP Accuracy ±2% at 23±5°C.
PDL 0.45 dB typical (90 ps version)
0.5 dB typical (180 ps version)
Wavelength Dependent Loss 0.6 dB (across C-band)
Transient Loss 0.6 dB (typical)
Electrical Characteristics:
Power Supply 100-240 VAC, 50-60 Hz
Communication Interfaces USB, Ethernet, RS-232, and GPIB
Response Time 1 ms (typical)
Front Panel Display 2 ×20 character LCD
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Section 2. Overview:
General Photonics’ PMDPro™ is a breakthrough PMD source that can deterministically
generate precise 1st-order PMD up to 180 ps and 2nd-order PMD up to 8100 ps2. It
combines this basic functionality with a rapid switching time (~1 ms) and polarization
optimization capability to enable various applications related to high bit-rate optical fiber
communication links. PMDPro simplifies and expedites all PMD related systems testing.
Figure 1 System diagram of polarization optimized PMD source
The PMDPro contains an automatic polarization controller and two polarimeters that
continuously monitor the state of polarization (SOP) and degree of polarization (DOP)
before and after the PMD generating elements. The polarization controller can be
operated using feedback from the input polarimeter to automatically align and maintain
the input SOP such that there is an equal power split between polarization components
aligned to the principal axes of the DGD element to obtain the worst-case first order
PMD effect. Alternatively, the controller can automatically adjust and maintain the input
SOP using the feedback from the output polarimeter to either minimize or maximize the
output DOP for each PMD setting.
Minimizing the output DOP enables testing of the worst-case total PMD effect, while
maximizing the output DOP allows the PMDPro to act as a PMD compensator, allowing
the user to determine the optimum PMD values for PMD compensation. The PMDPro
can also perform PMD emulation by generating statistical distributions of first and
second order PMD representing those of a real fiber link. In addition, the integrated
polarization controller and polarimeters enable variable rate scrambling and deterministic
polarization control functions, including trace generation and polarization stabilization at
any SOP.
Basic functions can be controlled either manually from the front panel keypad or
remotely via RS-232, USB, Ethernet, or GPIB interfaces. The control program also
enables several advanced functions.
The structure, features, and functions of the PMDPro are described in more detail in
sections 3 and 4. Section 5 includes application examples, and section 6 describes basic
troubleshooting.
DSP
Polarimeter2Polarimeter1PC 1s
t
& 2n
d
order PMD Generator
Interfacing electronics
Input Output

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Section 3. Feature Description:
3.1 Optical Features:
The PMDPro system has two bulkhead adapters on the front panel to accommodate the
optical input and output. The adapters are universal connector interfaces (UCI), which
feature a male-type adapter top piece that can be removed for direct access to the ferrule
end for routine cleaning and maintenance without removing the entire adapter from the
panel. This feature helps avoid high insertion loss, high return loss and measurement
instability caused by dirty or contaminated connectors. In addition, the PMDPro’s
universal interchangeable adapter allows the end user to switch to ST, SC, or FC
connectors without opening the instrument panel. Although the PMDPro is shipped with
a standard (typically FC/PC or FC/APC) fiber adapter, other interchangeable inserts are
available. For additional information on different input fiber adapter inserts, please
contact General Photonics.
External fiber connectors should be cleaned using industry standard cleaning methods
before connection to the PMDPro. If this procedure is followed before each connection,
the instrument’s internal connector ferrules should not need regular cleaning. However,
high insertion loss or measurement instability that does not improve after cleaning the
external connectors may indicate that the instrument’s internal connector ferrules require
cleaning.
Each connector ferrule is contained in a universal connector interface consisting of a
front piece that connects to the external fiber connector, and a base piece that is mounted
on the front panel of the instrument, as shown in Figure 2. To clean a connector ferrule,
first, make sure no external connector is connected to the universal connector interface.
Then, using a Phillips screwdriver, remove the two small screws connecting the front and
back parts of the adapter, and carefully pull the front flange straight out. (Note: never
remove the adapter base from the front panel). The ferrule end should now be exposed.
Clean the ferrule using standard cleaning procedures (compressed air or a fresh lint-free
tissue and alcohol), taking care to avoid scratching the ferrule surface. Finally, replace the
front flange (position it so that the key notch faces up, and the small alignment pin lines
up with the hole in the base piece, before pushing it in) and the screws. For frequent
measurements, we recommend that the user prepare a patch cord fiber to avoid wear on
the internal connector.
Figure 2 Diagram of universal connector interface
Hole for
alignment pin
Ferrule end
Remove screws
Front flange
Adapter base-
do not remove

Input power should be between –10 and +10 dBm.
3.2 Electrical Features:
The PMDPro system uses a power supply that accepts 100-240 VAC, 50-60 Hz line
voltages. Due to high voltage, the following safety precautions must be exercised during
operation.
•The ground pin on the power supply cord must be connected to earth ground of
the wall receptacle.
•Never touch the boards inside the package without proper insulation.
•The PMDPro is not user serviceable. It should be serviced only by factory-
authorized personnel.
The front panel of the PMDPro is shown in Figure 3. The power switch (Power), liquid
crystal display (LCD), push button control pads, and input/output optical connectors are
mounted on the front panel. The AC power plug, fuse, chassis ground connector, RS-232,
USB, Ethernet, and GPIB interface connectors, and two fans are mounted on the rear
panel, as shown in Figure 4.
The PMDPro includes RS-232, USB, Ethernet, and GPIB interfaces for external
computer operation of the system and data readout. RS-232 and USB cables are provided
for connecting the PMDPro to a personal computer. A LabView™ (National Instruments,
www.ni.com) control program compatible with all of the control interfaces is provided.
Control commands and control program installation and operation instructions are located
in Section 4.3.
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Figure 3 Front panel layout
Front panel description:
LCD display: displays data and operation mode information
Power: power on/off switch
Input: universal connector interface adapter for optical fiber input
Output: universal connector interface adapter for optical fiber output
Keypad: control button descriptions:
PMDE: DGD/PMD setting, scan, and emulation functions
SOP: Polarization control, waveform, and scrambling functions
WSOP Automatic input polarization alignment for worst-case PMD effect
MONITOR: Displays SOP and DOP readings from input and output
polarimeters, as well as output power and PMD information
PMDC: DGD and PMD compensation functions
MANUAL: SOP control via direct, real-time setting of individual polarization
controller channel voltages
STORE: Allows user to store sequences of PMD values for scans, or to
store individual PMDC measurement results
RECALL: Allows user to recall stored PMD sequences or PMDC
measurement results.
SETUP: Allows user to set basic system parameters: operation wavelength
(ITU channel), GPIB address.
ESC: Steps back to screen one level up from currently displayed screen.
ENTER (center key in arrow keypad): Enters parameters set with arrow keys
▲
◄►: Arrow keys used to set measurement/control parameters.
▼
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Figure 4 rear panel layout
Rear panel description:
USB: USB interface port
RS-232: serial communication port
Ethernet: Ethernet interface port
BNC: not used in PMD-1000
GPIB: GPIB interface port
Line: external AC supply input connector, 100-240VAC
: chassis ground connector
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